// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_CONTROLLER_H_
#define UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_CONTROLLER_H_

#include <set>

#include "base/strings/string16.h"
#include "ui/base/dragdrop/os_exchange_data.h"
#include "ui/views/views_export.h"

namespace ui {
class KeyEvent;
class MouseEvent;
class SimpleMenuModel;
} // namespace ui

namespace views {

class Textfield;

// This defines the callback interface for other code to be notified of changes
// in the state of a text field.
class VIEWS_EXPORT TextfieldController {
public:
    // This method is called whenever the text in the field is changed by the
    // user. It won't be called if the text is changed by calling
    // Textfield::SetText() or Textfield::AppendText().
    virtual void ContentsChanged(Textfield* sender,
        const base::string16& new_contents) { }

    // This method is called to get notified about keystrokes in the edit.
    // Returns true if the message was handled and should not be processed
    // further. If it returns false the processing continues.
    virtual bool HandleKeyEvent(Textfield* sender,
        const ui::KeyEvent& key_event);

    // This method is called to get notified about mouse events in the edit.
    // Returns true if the message was handled and should not be processed
    // further. Currently, only mouse down events are sent here.
    virtual bool HandleMouseEvent(Textfield* sender,
        const ui::MouseEvent& mouse_event);

    // Called before performing a user action that may change the textfield.
    // It's currently only supported by Views implementation.
    virtual void OnBeforeUserAction(Textfield* sender) { }

    // Called after performing a user action that may change the textfield.
    // It's currently only supported by Views implementation.
    virtual void OnAfterUserAction(Textfield* sender) { }

    // Called after performing a Cut or Copy operation.
    virtual void OnAfterCutOrCopy(ui::ClipboardType clipboard_type) { }

    // Called after performing a Paste operation.
    virtual void OnAfterPaste() { }

    // Called after the textfield has written drag data to give the controller a
    // chance to modify the drag data.
    virtual void OnWriteDragData(ui::OSExchangeData* data) { }

    // Called after the textfield has set default drag operations to give the
    // controller a chance to update them.
    virtual void OnGetDragOperationsForTextfield(int* drag_operations) { }

    // Enables the controller to append to the accepted drop formats.
    virtual void AppendDropFormats(
        int* formats,
        std::set<ui::Clipboard::FormatType>* format_types) { }

    // Called when a drop of dragged data happens on the textfield. This method is
    // called before regular handling of the drop. If this returns a drag
    // operation other than |ui::DragDropTypes::DRAG_NONE|, regular handling is
    // skipped.
    virtual int OnDrop(const ui::OSExchangeData& data);

    // Gives the controller a chance to modify the context menu contents.
    virtual void UpdateContextMenu(ui::SimpleMenuModel* menu_contents) { }

protected:
    virtual ~TextfieldController() { }
};

} // namespace views

#endif // UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_CONTROLLER_H_
